1. Field of the Invention
This invention relates to an organic compositions consisting at least in part of glycerol polycarbonates.
The invention relates to glycerol polycarbonate extracted from the organic composition.
The invention also relates to the organic composition including glycerol polycarbonates, in a mixture with polyglycerols, [(α-hydroxymethyl)oxyethylene/(α-hydroxymethyl ethylene carbonate) copolymers; optionally [(α-alkyl)oxyethylene/(α-alkyl)ethylene carbonate] copolymers, optionally [(α-alkyl)oxyethylene/(α-hydroxyalkyl)oxyethylene] copolymers, glycerol carbonate and/or other organic carbonates, glycerol and/or other co-produced and/or residual compounds.
The invention also relates to a method for producing the organic composition, by catalytic polymerisation in a heterogeneous reaction medium comprising an organic liquid phase made up of at least one compound providing hydroxyl functions and at least one compound providing carbonate functions, a solid phase that may or may not be solubilised formed by a catalyst containing active sites in the Lewis or Bronsted sense and an ambient gaseous phase formed by gas products in situ.
The invention also relates to a method for the separation extraction of each constituent of the organic composition, and, in particular, for the extraction of the glycerol polycarbonate, or polyglycerol or [(α-hydroxymethyl)oxyethylene/(α-hydroxymethyl)ethylene carbonate] copolymers or [(α-alkyl)oxyethylene/(α-alkyl)ethylene carbonate] copolymers, or [(α-alkyl)oxyethylene/(α-hydroxyalkyl)oxyethylene] copolymers.
The invention finally relates to the use and application, in numerous fields, of the organic composition, or of each of its extracted constituents, owing to the numerous specific characteristics such as tribological multifunctionality, non-toxicity to humans, animals and the environment, biodegradability, thermal stability, resistance to oxidation and hydrolysis, high wettability, rheological properties, electrical conductivity, hydrophilic and water-soluble characteristics, and so on. Without being exhaustive, it is possible to cite fields such as motor vehicle and industrial lubricants and lubricating additives, more specifically those intended for metal working or machining, hydraulic fluids, more specifically fire-resistant, as additives, mould-release agents, wood treatment products, additives for drilling mud, detergency, wetting additives, thickeners and dispersing agents, pharmacy, cosmetics, food, and so on, and finally as chemical synthesis intermediates.
2. Description of Related Art
It is known that glycerol is an organic compound produced in large amounts in industrial-scale transformations of oils and grease into soaps, fatty acids, fatty esters and in particular, fatty acid methyl esters. The latter is produced for the development of biofuels.
Glycerol therefore appears to be an available starting material of interest due to its low cost and intrinsic qualities.
This is why much research and development, focusing on the processing of glycerol as is, or, preferably, in a chemically transformed state, has been conducted.
One of the chosen methods for this transformation is heterocyclisation of the glycerol, which enables it to be transformed into glycerol carbonate with a greater added value in view of the applications in which glycerol carbonate has been shown to be effective owing to its excellent intrinsic characteristics. Glycerol carbonate is indeed a compound that is:                bi-functional, enabling it to act as a solvent with regard to numerous organic or inorganic compounds,        non-toxic with a high boiling point,        capable of being used as a polymer stabilisation additive and synthesis intermediate in organic reactions such as esterifications, transesterifications, carbamoylation and other reactions,        capable of being implemented in numerous fields such as cosmetics, pharmacy and food.        
A number of methods for performing the heterocyclisation of glycerol by carbonation are proposed in the prior art, all showing the benefits of said heterocylisation.
A first document (U.S. Pat. No. 2,915,529) describes a method for synthesis of glycerol carbonate, by reacting glycerol with an organic carbonate, such as ethylene carbonate or propylene carbonate in a homogenous catalyst, in the presence of an alkaline base, at a temperature of between 125° C. and 135° C. The reaction medium gives, at the end of the reaction, a mixture made up of glycerol carbonate, ethyleneglycol, an alkaline base used as the catalyst, glycerol and ethylene carbonate. But the extraction of the glycerol carbonate from the aforementioned reaction medium obtained, creates a major disadvantage because this extraction is difficult to implement: it indeed requires an acid neutralisation followed by a vacuum distillation in the presence of glycerol contaminated by the products resulting from the neutralisation. In addition, this method developed on an industrial scale has another disadvantage, which is the implementation, as a carbonate source for the reaction, a costly reagent: organic carbonates. Finally, this method leads solely to the production of glycerol carbonate.
Another document (EP 0739888) describes a method for producing glycerol carbonate from glycerol and cyclic organic carbonate, by reacting these compounds in a solvent medium constituted by an organic carbonate or a mixture of organic carbonates, in the presence of a solid catalyst including a bicarbonated or hydroxylated anionic macroporous resin, or an X or Y three-dimensional zeolite comprising basic sites, at a temperature of no more than 110° C. In this method, the ethylene and/or propylene carbonates are preferably used as reactive starting carbonates because they produce higher reaction kinetics, and the co-product of the carbonation reaction, which is a diol, is drawn off of the reaction medium as it forms.
By combining the aforementioned means, in particular by combining the reaction in a solvent medium formed by organic carbonates, containing a heterogeneous catalyst and removing the diol formed, the method makes it possible to obtain almost exclusively highly-concentrated glycerol carbonate without organic polycarbonates appearing in the reaction medium.
Another document (FR 2 778 182) describes a method for producing glycerol carbonate by a carbamoylation/carbonation catalytic reaction of glycerol, which consists of reacting urea and glycerol at a temperature of between 90° C. and 220° C. in the presence of a catalyst, constituted by at least one metal salt containing Lewis acid sites.
This reaction is produced by the following two-step mechanism:Urea+glycerol->glycerol carbamate+ammonia  (1)Glycerol carbamate->glycerol carbonate+ammonia  (2)
The reaction, according to the two aforementioned steps, is preferably performed under vacuum, in particular at a pressure of between 3.103 Pa and 2.104 Pa, so as to move the reaction medium in order to eliminate the ammonia gas generated.
The catalyst implemented in the method described is chosen from the group constituted by metal sulphates, such as zinc sulphate, manganese sulphate, magnesium sulphate, nickel sulphate, iron sulphate, cobalt sulphate, sodium sulphate, having Lewis acid sites, with the catalytic activity: these metal sulphates are implemented alone or in supported forms.
The method proposed for producing glycerol carbonate by a catalytic reaction of two compounds, which are glycerol and urea, is thus more economically advantageous and therefore industrially applicable owing to the low costs of the starting materials used. But the method is limited exclusively to the production of glycerol carbonate.
Thus, the prior art already shows that it is known how to produce glycerol carbonate, just as it was known how to produce other organic carbonates such as ethylene carbonate.
However, the prior art also shows that some of these organic carbonates, such as, in particular, ethylene carbonate, were capable of being transformed into macromolecular polycarbonates, which are particularly advantageous in many areas of chemical applications.
A document (FR 1 182 439) actually describes a method for preparing macromolecular polycarbonates from cyclic carbonates (such as ethylene carbonate) with terminal hydroxyls, with molecular weights of between 700 g/mol and 5000 g/mol and presenting hydroxyl indices ranging from 20 to 170.
The method proposed consists of heating the ethylene carbonate with a polyhydric alcohol to temperatures of between 150° C. and 250° C. in the presence of a basic catalyst (potassium carbonate) with a CO2 emission. The ethylene polycarbonates resulting from this method have advantageous properties due to the presence of their numerous hydroxyl sites, which enable them to react, for example, with carboxylic acids, yielding polycarboxylic esters or compounds used in particular in moulding, rolling and textile coating operations. These polycarbonates can also react with isocyanates, yielding polyurethanes used in the creation of flexible or rigid polyurethane foams.
Other prior art documents [Polymer letters, vol. 14, p. 169-165 (1971) or Makromol. Chem. 191, 465-472 (1990)] mention other conditions by which ethylene (and propylene, in the second document) polycarbonate is obtained, which:                in the first document, consist of the catalytic polymerisation of the heterocyclic ethylene carbonate in the presence of a suitable catalyst, such as Ti (Obu)4         in the second document, consist of copolymerising methyloxirane with CO2.        
However, these documents propose means that involve more laboratory work than work intended for industrial development.
Finally, the prior art (U.S. Pat. No. 5,721,305) discloses that it is possible to produce glycerol polymers from glycerol, or from a compound such as 2,2 dimethyl-1,3-dioxolane-4-methanol, glycidol or glycerol carbonate, the polymerisation being performed in the presence of a hydrotalcite-type anionic clay. In the specific case of the use of glycerol carbonate as the starting material, it is desirable for the glycerol carbonate to be prepared by a reaction with glycerol and diethyl carbonate. The results of the analysis of the mixture resulting from the polymerisation (example 5) show that linear or cyclic oligomers of glycerol and glycerol monocarbonate dimers, or trimers or tetramers are obtained, whereas it might have been expected to obtain glycerol polycarbonates in the form of dimers, trimers or tetramers, which is not the case.
It therefore appears from this last document that glycerol carbonate cannot be used as a reaction material in a polymerisation method in order to obtain a glycerol polycarbonate in the form of oligomers, for example.
Thus, the methods proposed in the prior art describe means implemented for producing glycerol carbonate, but do not provide means to be implemented in order to obtain glycerol polycarbonates.